Specific allele types associated with poly-A tract in the promoter region of the brain cannabinoid receptor gene have been reported to be associated with intravenous opiate and cocaine and/or crack cocaine use but not with alcohol dependence. The goal of this project is to provide an independent examination of this report using a collection of drug and alcohol dependent subjects we have been studying at other candidate genetic sites. We will also extend the study to include examination of associations between alleles at the cannabinoid receptor gene promoter and primary drug dependence on cannibis. We have enrolled 9 cannabis-dependent only subjects during the last few months and have recently begun to analyze the DNA from our banked samples of 450 drug and alcohol dependent subjects at this allele. There are no reportable results to date from our sample as to the presence of associations at the cannabinoid marker under study and subtypes of substance dependence. During the next year we anticipate recruiting 40-50 additional cannabis dependent subjects and to complete the initial genotyping at the cannabinoid allele for these and our previously identified cohorts of drug and alcohol dependent subjects.